London has been battered by 50mph winds that have felled trees and caused travel chaos. Powerful gusts swept across the capital as the Met Office issued a yellow "be aware" weather alert for most of the country.

The chairman of a small London art gallery has told how he snapped up a £400,000 painting for less than a tenth of its value.

The London Jewish Museum of Art bought the work by Marc Chagall for £26,000 from under the noses of the world's major galleries at a Paris auction.

David Glasser, executive chairman of the museum, also known as the Ben Uri Gallery, said the bidding process was the "most nerve-wracking experience" in his 35 years as an art collector.

The 1945 work Apocalypse in Lilac, Capriccio is one of only 10 by Chagall created between 1938 and 1945 to feature a Jewish Christ. Some experts believe the work by the Russian-French artist could be worth more than £1million.

Mr Glasser said: "I thought it was an incredibly modest estimate when I saw it in the catalogue and I did not expect to get it. Either it would be bid out of reach or we thought the Museum of Modern Art in Paris would ask the French authorities to refuse an export licence because of its significance."

Although the auction was held last October, Mr Glasser has only now revealed the purchase, after receiving the painting, over fears the sale could be blocked.

He said: "It would have been very different if it was a New York or a London sale. It really is a coup for the UK. There are no other Chagall crucifixion works in this country.

"It was properly identified and catalogued but my guess is that they thought it would be hard to sell because it is such a difficult subject and macabre work from an artist normally associated with optimism and bright colours."

Apocalypse in Lilac, Capriccio does not yet have a permanent home as the Ben Uri Gallery, which houses about 1,000 works, is looking for a new central London base, having outgrown its existing premises in St John's Wood.

The painting will be unveiled at the Osborne Samuel gallery in Mayfair this week.